4. Onboard activities are free
Many cruise lines have begun charging extra for new premium amenities such as fancy alternative restaurants, small-group cooking classes, simulated-surf machines and elaborate exercise sessions. Whether you indulge in these offerings is up to you. Also, prepackaged offshore tours can be exorbitant if arranged by the cruise line. You can find and book your own activities and share transportation with other passengers to save money.

5. All cabins are alike
Wrong. An inside cabin (usually the cheapest) has no view; an outside cabin has a closed window or porthole; and a balcony/veranda cabin has a door opening to an outdoor space. And within these categories, there can also be many variations. Look into room layouts before booking. Also study the ship layout: You don't want to end up in a cabin under the nightclub, for instance (unless a disco beat helps put you to sleep).

6. You'll get seasick
If you suffer from motion sickness, you should be prepared with appropriate antinausea medication. That said, most ships — large and small — have stabilizers for a smooth ride. If the seas are calm, you'll feel little movement at all. And if you're still concerned, the aforementioned inside cabins might actually be a good bet for you.

7. Cruise ships are confining
This is off-the-charts false. Sure, you're at sea and can't just walk off the ship whenever you want. But it's highly unlikely you'll ever feel trapped. These days, some ships are the size of small towns, and most offer entertainment and activities of every kind — from the cerebral to the hedonistic — both day and night. Plus, you won't exactly be disconnected, thanks to the Internet access that's available most of the time.

Also of Interest 

• Tips on scoring the best cruise ship cabin
• Symptoms you shouldn't ignore

Remember to go to the AARP home page every day for tips on travel, vacations, and great deals.